[fpc-devel] Code generated for the embedded arm port for lpc1768 (armv7m)

[Michael Ring]

One more thing:

Did you try to run the code directly on the device after uploading it or 
did you use a debugger to start the program?

When I remember correcly all LPCxxx devices need a magic checksum so 
that they are started on the device. The creation of this checksum is in 
trunk, but I am pretty sure that it is not in release 2.6.4.

Michael

Am 23.10.14 um 20:52 schrieb Michael Ring:
> I remember seeing the problem that gdb does not correctly disassemble 
> code...
>
> Please do a
>
>  arm-none-eabi-readelf -A xxx.elf
>
> you should see:
>
> File Attributes
>   Tag_CPU_name: "7-M"
>   Tag_CPU_arch: v7
>   Tag_CPU_arch_profile: Microcontroller
>   Tag_THUMB_ISA_use: *Thumb-2*
>
> Compiling, linking and running is fine for me, difference in setup is 
> that I use another processor (stm32f407) and that I used trunk sources 
> to compile the crosscompiler.
> But as Jeppe already mentioned, this all should have worked fine with 
> 2.6.4 version too.
>
> And your commandline you used for both creating the crosscompiler / 
> build the program is exactly the same I use.
>
> Michael
>
> Am 23.10.14 um 20:15 schrieb Sietse Achterop:
>> Hello,
>> I am trying to get the embedded version of fpc for arm to work.
>> Currently i try it for the lpc1768 from NXP using the lpcxpresso board.
>> The example compiles, but doesn't run on the target...
>>
>> I created a simple example and it seems that the code it generates is 
>> NOT thumb2 code.
>> I disassembled the elf-file generated by fpc using 
>> "arm-none-eabi-objdump -S"
>> I also disassembled it using the debugger "arm-none-eabi-gdb"
>> Here is a fragment of the code from both:
>>
>> From objdump:
>> 000001c4 <FPC_INITIALIZEUNITS>:
>>  1c4:    e92d4070     push    {r4, r5, r6, lr}
>>  1c8:    ebfffff5     bl    1a4 <SYSTEM_$$_FPC_CPUINIT>
>>  1cc:    e59f006c     ldr    r0, [pc, #108]    ; 240 
>> <FPC_INITIALIZEUNITS+0x7c>
>>  1d0:    e5904000     ldr    r4, [r0]
>>  1d4:    e3a05001     mov    r5, #1
>>  1d8:    e1540005     cmp    r4, r5
>>  1dc:    ba00000f     blt    220 <FPC_INITIALIZEUNITS+0x5c>
>>
>> From gdb
>>    0x000001c4 <fpc_initializeunits+0>:        70 40 eors             
>> r0, r6
>>    0x000001c6 <fpc_initializeunits+2>:        2d e9 f5 ff             
>> stmdb    sp!, {r0, r2, r4, r5, r6, r7, r8, r9, r10, r11, r12, sp, lr, 
>> pc}
>> => 0x000001ca <fpc_initializeunits+6>:        ff eb 6c 
>> 00                          ; <UNDEFINED> instruction: 0xebff006c
>>    0x000001ce <fpc_initializeunits+10>:        9f e5 
>> b.n                     0xfffffd10
>>    0x000001d0 <fpc_initializeunits+12>:        00 40 
>> ands                     r0, r0
>>    0x000001d2 <fpc_initializeunits+14>:        90 e5 
>> b.n                     0xfffffcf6
>>    0x000001d4 <fpc_initializeunits+16>:        01 50 
>> str                     r1, [r0, r0]
>>    0x000001d6 <fpc_initializeunits+18>:        a0 e3 
>> b.n                     0x91a
>>    0x000001d8 <fpc_initializeunits+20>:        05 00 
>> movs                     r5, r0
>>    0x000001da <fpc_initializeunits+22>:        54 e1 
>> b.n                     0x486
>>    0x000001dc <fpc_initializeunits+24>:        0f 00 
>> movs                     r7, r1
>>
>> Note how the interpretation of the code is different, as is the 
>> length of most instructions.
>> It looks to me as if the code in the elf-file are (mostly) 32-bit 
>> values, while the debugger does interpret thee code as thumb2 (i think).
>>
>> In the Makefile in rtl/embedded I find:
>>
>>     ifeq ($(SUBARCH),armv7m)
>>     CPU_UNITS=lm3fury lm3tempest stm32f10x_ld stm32f10x_md 
>> stm32f10x_hd stm32f10x_xl stm32f10x_conn stm32f10x_cl lpc13xx lpc1768 
>> lm4f120  xmc4500 cortexm3 cortexm4 # thumb2_bare
>>     endif
>>
>> So that suggest (via the comment) that fpc can do thumb2 code, which 
>> it should for cortexm3.
>>
>> My PC is debian/jessie/64bit:  Free Pascal Compiler version 
>> 2.6.4+dfsg-3 [2014/07/12] for x86_64
>> I got the sourcecode for the port from svn as described on the website.
>> To create the port I do:
>>
>>     make clean buildbase installbase CROSSINSTALL=1 
>> OS_TARGET=embedded CPU_TARGET=arm SUBARCH=armv7m 
>> BINUTILSPREFIX=arm-none-eabi-
>>
>> For the binutils I use the (current) stuff for the lpc1768 from NXP: 
>> lpcxpresso_7.4.0_229
>>
>> To create a program I do:
>>
>>     ppcrossarm -Ch1024 -Cs1024 -Tembedded -Parm -Cparmv7m 
>> -XParm-none-eabi- -Wplpc1768 -vu prog.p
>>
>> Is there anybody that did get this port to work?
>>
>>   Thanks in advance,
>>        Sietse
>>
>>
>>
>> _______________________________________________
>> fpc-devel maillist  - fpc-devel at lists.freepascal.org
>> http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
>
>
>
> _______________________________________________
> fpc-devel maillist  -  fpc-devel at lists.freepascal.org
> http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freepascal.org/pipermail/fpc-devel/attachments/20141023/b8345fea/attachment.html>